110189 NV-MOJ May 08 01-07 G5H.qxd

Total hip replacement has consistently been shown to be one of the most reliable and successful surgical procedures in orthopaedic surgery . However time, the longevity of total hip replacement implants may be limited by osteolysis and aseptic loosening regardless of the method of fixation . Osteolysis manifests itself by causing progressive periprosthetic bone resorption secondary to the biological response to particulate wear debris that is generated by the implant. Historically, osteolysis, also referred to as “cement disease”, was considered to be the result of bone resorption secondary to the fragmented cement . Previously published studies, on the other hand, have demonstrated that the periprosthetic osteolytic process stems from a combination of foreign body cellular responses to particulate wear debris. The debris may be generated from the articulating surfaces, fixation surfaces, modular component junctions, or acetabular screws . Particulate wear debris from total hip replacements is predominantly generated by adhesive, abrasive or fatigue mechanisms.